Cosmetic brush



FIG. 1 is a perspective view of a cosmetic brush embodying our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a front elevation view thereof; and,

FIG. 7 is a back elevation view thereof.

The broken lines shown in the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a cosmetic brush, as shown and described. 